At Lake Tahoe, at an elevation of six thousand feet, Dr. Cooper found the young of this species quite common near the middle of September. Supposing them to be the more common S. rufus, he only obtained a single specimen. He thinks that these birds extend their northern migrations as far as the Blue Mountains, near Snake River, Oregon, and that they are the ones referred to by Nuttall as seen by him in autumn, and supposed to be the rufus.
The nests of this species procured by Dr. Palmer were large for the size of the bird, unusually broad and shallow, composed of soft downy pappus from seeds of plants, and vegetable down, with the outer walls covered with mosses and lichens. The eggs are not distinguishable from those of the other species.
The Rocky Mountain or Broad-tailed Hummer, according to Mr. Ridgway’s observations, is the most abundant species in the Great Basin, though he did not see it to recognize it west of the East Humboldt Mountains. It is essentially a bird of the mountains, since in that region there are few flowers elsewhere; yet in the gardens of Salt Lake City, an altitude far below its usual habitat, it was abundant. Its favorite resorts are the flowery slopes of the higher and well-watered mountain-ranges of the Great Basin and Rocky Mountain system, at an average elevation of about eight or nine thousand feet, yet it will be found wherever flowers are abundant. Mr. Ridgway saw one at an altitude of about twelve thousand feet, in July, on the East Humboldt Mountains, but it merely passed rapidly by him. In the Wahsatch Mountains, particularly in the neighborhood of Salt Lake City, this species was most plentiful. It there nested abundantly in the scrub-oaks on the hills or slopes of the cañons.
The male bird is very pugnacious, and was observed to attack and drive away an Accipiter fuscus, the Hawk retreating as rapidly as possible. When the nest is approached, the male often rises high into the air and then sweeps down almost to the head of the intruder, its swift descent being accompanied by a very peculiar shrill, screeching buzz, of an extraordinary degree of loudness to be produced by so small a creature. The same sound Mr. Ridgway noticed when the bird was passing overhead, in a manner not observed in any other species, its horizontal flight being by a peculiar undulating course. The shrill noise made by the male of this species he suggests may be caused by the curious attenuated and stiffened outer primary. He noticed a curious piece of ingenuity in nest-making on the part of this species. The nest in question was fastened upon a dead twig of a small cottonwood-tree; the loosening bark, which probably had separated after the nest was finished, had allowed the nest to turn around so as to hang beneath the branch, thus spilling the eggs upon the ground. The owners, however, built another nest upon the top of the branch, fastening its sides to that of the old one, and making the new nest lighter and less bulky, so that the weight of the older nest kept the other in a permanently upright position.
Genus ATTHIS, Reichenbach.
Atthis, Reich. Cab. Jour. f. Orn. extraheft für 1853, 1854. Appendix B. (Type, Ornysmya heloisa, Lesson, Del.)
Atthis heloisa.
25874 ♂ 24618 ♀
Gen. Char. Size very diminutive; bill short, scarcely longer than the head. Outer primary attenuated nearly as in Selasphorus; the tail graduated, the feathers, however, not lanceolate-acute, but rounded at end, and tipped with white in the male.
This genus seems closely related to Selasphorus, agreeing in character of throat, the curious attenuation of outer primary, and the general shape of the tail, with its rufous base and edging. The feathers, however, are not lanceolate and pointed, either sharply as in S. rufus, or obtusely as in platycercus, but are more equal to near the end, where they round off. The white tip of the tail in the male seems to be the principal reason why Mr. Gould removes the single species from Selasphorus, where it was previously placed by him, and where perhaps it might have not inappropriately remained.